Metal halide containing zeolites and method for their preparation

ABSTRACT

This disclosure relates to novel metal halide containing zeolites, particularly crystalline aluminosilicate zeolites and methods for their preparation. Such materials are prepared by treating alkali or alkaline earth forms of crystalline aluminosilicate zeolites with a volatile halide of a less positive metal or nonmetal than the alkali or alkaline earth metals under relatively anhydrous conditions. The resulting products may be used as formed or may be washed free of soluble halides prior to use. Utility for these materials is to be found as adsorbents, particularly selective adsorbents and as catalysts for acid-catalyzed reactions such as catalytic cracking, alkylation, polymerization, isomerization and other carbonium ion type reactions.

United States Patent Kearby 5] Feb. 22, 1972 METAL HALIDE CONTAININGZEOLITES AND METHOD FOR THEIR PREPARATION Kenneth K. Kearby, Watchung,NJ. Assignee: Esso Research and Engineering Company Filed: Nov. 13, 1969Appl. No.: 871,627

Inventor:

Related U.S. Application Data Continuation of Ser. No. 672,690, filedOct. 4, 1967, abandoned.

US. Cl. ..252/442, 252/455 Z Int. Cl. .B0lj 11/78, 801 1 1/40 Field ofSearch ..252/442, 4552 References Cited UNITED STATES PATENTS l/ 1967Korvach ..252/442 X 5/1967 Martin 1l/l967 Miale et al. 9/1968 Leftin etal ..252/455 X 3,477,965 1 l/ 1969 Fishel ..252/442 PrimaryExaminer-Daniel E. Wyman Assistant Examiner-C. F. DeesAttorney--Pearlman and Stahl and George M. Gould ABS I'RACT lyzedreactions such as catalytic cracking, alkylation,

polymerization, isomerization and other carbonium ion type reactions.

24 Claims, No Drawings METAL HALIDE CONTAINING ZEOLITES AND METHOD FORTHEIR PREPARATION BACKGROUND OF THE INVENTION It has now been wellestablished in the art that the properties of crystallinealuminosilicate zeolites can be altered by treating them with variousmetal or nonmetal compounds. For example, in U.S. Pat. Nos. 2,971,903and 2,971,904 the activity and selectivity of crystallinealuminosilicate zeolite hydrocarbon conversion catalysts can be improvedby treating such materials with aqueous solutions of the alkaline earthmetals, platinum group metals or the iron group metals. In the U.S. Pat.No. 2,971,904 in particular the crystalline aluminosilicate zeolitesserve as supports for metal compounds which of themselves havesubstantial catalytic activity. Additionally, it has been found that thesize of the uniform pores of a crystalline aluminosilicate zeolite canbe altered by replacing some of the cations in the window positions inthe zeolite with another metal cation having a different ionic radiusthereby either increasing or decreasing the effective diameter of theopenings. Such a technique is described in U.S. Pat. No. 3,282,028. Asin the previous examples, the metal interchange with the zeolite isaccomplished by placing the zeolite in contact with an aqueous solutionof the metal cation to be introduced.

Still another technique for introducing metals into crystallinealuminosilicate zeolites involves an ion exchange step followed byreduction of the metal ion to the metal form inside the inner adsorptionregions of the zeolite. Whereas the previous methods presented the metalin either the cationic or a covalent compound form, patentees here teachthe use of a dispersed form of the elemental metal.

Yet another technique is taught in U.S. Pat. No. 3,013,990 whereincrystalline aluminosilicate zeolites are ion exchanged with a complexcation form of a metal. The exchanged form of the zeolite is then heatedat elevated temperatures to decompose the complex and yield theelemental form of the metal in the inner adsorption region of thezeolite. This technique is limited to relatively wide pore crystallinealuminosilicate zeolites since the complex metal cations cannot passthrough small pore zeolitic materials. Once again, the catalyticallyactive form of the metal in the zeolite is the elemental form.

U.S. Pat. No. 3,013,987 discloses yet another technique for metalloading of crystalline aluminosilicate zeolites, This technique involvestreating the zeolites with decomposable fluid metal compounds. Themetals used include those of groups [-8, ll-A, lll-A, lV-A, lV-B, Vl-B,VII-B and Vlll of the Periodic Table (Handbook of Chemistry and Physics,31st Ed., p. 336, Chemical Rubber Publishing Company, 1949). Thereducible compounds of thesemetals include the carbonyls, carbonylhydrides, acetyl acetonate complexes of the metals in the zero valencestate, reducible halides, metal alkyls and other metal-organic compoundssuch as cyclopentadienyl metal compounds and ethylenic complex compoundsof the noble metals. As in the previous cases, the decomposable metalcompounds are converted to the elemental metal form in the inneradsorption regions of the zeolite by either heat treatment or bytreatment with a reducing agent. The reference further teaches that bestresults are obtainable when much of the water of crystallization of thezeolite is removed prior to treating with the decomposable fluid metalcompound.

SUMMARY OF THE INVENTION The present invention is concerned with a newclass of metal containing crystalline aluminosilicate zeolites which areuseful as adsorbents and as catalysts particularly in petroleumhydrocarbon conversion processes. The novel crystalline aluminosilicatezeolites of the present invention are obtained by reacting an alkali oralkaline earth or hydrogen form of the aluminosilicate zeolite with thevolatile halide of a less positive metal or nonmetal than the alkali oralkaline earth metals which are present in the cation exchange sites ofthe zeolite. In

order to obtain best results in the foregoing reactions, it is desirablethat the crystalline aluminosilicate be dried'by treating the materialat elevated temperatures, e.g., in the range between 400 to 1,200" F.for a sufficient time so as to remove substantially all of the adsorbedwater contained in the zeolitic pores. It is further desirable toconduct the reaction between the volatile halide and the metal orhydrogen containing crystalline aluminosilicate zeolite under relativelyanhydrous conditions. Since the anhydrous metal halide will react withwater to form the metal oxide, any water present requires thatadditional metal halide be used. Preferably, the water content shouldnot be over 0.1 percent of the weight of the zeolite. The resultingproduct may be used as formed or may be washed free of soluble halidesdepending on its intended use.

The crystalline aluminosilicate zeolites useful in the present inventionare now well known in the adsorption and catalytic arts and many formsof such zeolites are now staplesof commerce. Among the preferredaluminosilicates one can include Zeolites A, faujasite (both the naturalform and the synthetic form marketed as Zeolite Y by the Linde Divisionof Union Carbide), L, -D, R, S, T, Z, E, F, O, B, X, levynite,dachiarite, erionite, analcite, paulingnite, noselite, phillipsite,brewsterite, flakite, datolite, chabazite, gmelinite, lucite, scapolite,mordenite, ZK4, Zeolite alpha and ZK-S. In their hydrated form thealuminosilicates may be represented by the r a:

wherein M represents at least one cation which balances theelectrovalence of the alumina tetrahedra, n represents the valence ofthe cation, w the moles of Si0 and Y the moles of H 0. The cation can beone or more of a number of metal ions depending upon whether thealuminosilicate is synthesized or occurs naturally. The particularlypreferred aluminosilicates are those having uniform pore diameters ofatleast about 4A. It is further preferred to utilize those crystallinealuminosilicate zeolites having silica to. alumina mole ratios greaterthan about 3. Included in this group are synthetic faujasite, erioniteand mordenite.

The volatile halides used to form the noveladsorbents and catalysts ofthe present invention include the volatile halides of metal elementssuch as aluminum, zirconium, titanium, tin, molybdenum, tungsten,chromium, vanadium, antimony, bismuth, iron, platinum, palladium and therare earths. It is further within the scope of the present invention toutilize halides of nonmetals to introduce such materials intocrystalline aluminosilicate zeolites in catalytically active forms. Forexample, the halides and oxy halides of arsenic, silica, boron orphosphorus, may be utilized to introduce these elements into thezeolitic structure. Specific examples of preferred nonmetallic compoundsfor this purpose include AsCl SiCl SiOCl BCl and PCl It is also possibleto utilize the less volatile metal halides of metals such as copper andzinc. The halides of copper and zinc are believed to react by surfacediffusion with the zeolitic material rather than by a mechanism ofvolatilization of the halide. Bromides, iodides and some fluorides ofmany metals are sufficiently volatile to be used, but chlorides areusually preferred because of their lower cost.

It is believed that the metal or nonmetal halides react with either thealkali metal or hydrogen form of the zeolites as per the followingequations which utilize aluminum chloride as the tr a in asse e rq v s vamp e only [Zeolite] M A101 [Zeolite] A101 M01 or [Zeolite]; AlCl 2MC1or [Zeoliteh Al -l- 3MCl where M Na K H etc.

Suitable changes in the above representation would be obvious if M werea polyvalent cation such as Mg or Ca.

It is evident, of course, that the extent of substitution on the metalhalide or nonmetal halide atom will be limited by the valence state ofsuch atom. The above representation, of course, should not be taken assuggesting that several zeolite crystal structures are ionically bondedto one metal atom, e.g., aluminum, but rather that the polyvalentaluminum atom may be satisfying the ionic charges on several sides ofthe zeolitic crystal lattice.

It is desired that in effecting the metal or nonmetal halide treatmentof the crystalline aluminosilicate zeolites of the present inventionthat from 0.1 to 3 stoichiometric equivalents of halide ion be used perequivalent of exchangeable hydrogen, alkali or alkaline earth metal inthe zeolite. More preferably, it is desirable to utilize from 0.5 to 1.5equivalents of metal or nonmetal halide per equivalent of alkali metalor hydrogen ion in the zeolite. In cases where the metal or nonmetalhalide has intrinsic catalytic activity such as for example when suchmaterials are Lewis acids, a molar excess of these materials isbeneficial. This molar excess results in excess adsorbed metal ornonmetal halide on the surface of the zeolite thereby enhancing thecatalytic properties of the resulting catalyst deposit. A particularexample of interest would be the utilization of aluminum chloride as thetreating agent. An excess of aluminum chloride would result in havingaluminum chloride present on the zeolitic surfaces where this materialcould function in a catalytic process such as in a Friedel-Crafttypereaction. For example, excess AlCl on a Pt or Pd containing zeolite willenchance its hydroisomerization and hydrocracking activity.

it is interesting to note that treatment of the crystallinealuminosilicate zeolites with the volatile metal or nonmetal halides inaccordance with the present invention results in the uptake of the metalor nonmetal halides in a form which partially resists removal by washingwith water. it is thus possible to wash the treated zeolites so as toremove any alkali metal halide or hydrohalide acid which may have beenformed during the replacement of the exchangeable cations with thevolatile metal or nonmetal halides. It is believed that washing thehalide treated products results in the replacement of some of theremaining halogen on the metal or nonmetal attached to the zeolite withacidic OH groupsrsuch acidic OH groups would be effective as carboniumion initiators which would make such materials exceptionally useful incarbonium ion reactions such as cracking, disproportionation,isomerization, alkylation, etc. It is further contemplated to utilizesuch treated zeolites in conjunction with hydrogenation components suchas platinum, palladium, nickel, cobalt, molybdenum, tungsten, etc., inprocesses wherein both a hydrogenation and acidic functional catalyst isrequired, e.g., hydrocracking, hydroisomerization, hydrodealkylation,etc. For example a hydrogen faujasite containing 0.1 to 1.0 percent ofPt or Pd is treated with l to 20 percent AlCl or AlBr at 400 to l,000 F.to give active hydroisomerization catalysts.

The powdered form of the zeolite tobe treated with metal halide ispreferably calcined at about 800 to l,000 F. to remove most of itscontained water. It is then thoroughly mixed with powdered metal halideunder anhydrous conditions. The mixture is preferably stirred or tumbledwhile being heated. This disperses the metal halide and reacts it withthe zeolite. The calcination temperature is preferably about 500 to1,000 F. for one-half to about 5 hours. Alternatively, the vaporizedmetal halide may be passed through a bed of the powdered or granularzeolite. This procedure is preferred with low boiling liquid halidessuch as SiCl,,, TiCl AsCl etc. These treatments may be at atmospheric,subatmospheric or at elevated pressures up to 1,000 p.s.i.g.

A DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific embodiments ofthe present invention may be more clearly understood by reference to thefollowing examples.

EXAMPLE 1 This example demonstrates the preparation of an aluminumchloride treated sodium faujasite crystalline aluminosilicate zeolite.

A quantity of synthetic faujasite in the sodium form obtained from theLinde Division of Union Carbide and designated by them as Linde l3-Ytype molecular sieve was calcined for 15 hours at l,000 F. to reduce its20 percent water content below 0. 1 percent. Portions of this driedmaterial were then treated with increasing amounts of aluminum chloridevapors. The treated crystalline aluminosilicate zeolite was then heatedfor 16 hours at 450l,000 F. under a dry nitrogen atmosphere. it wasobserved that no significant amount of aluminum chloride volatilized outof the leaner mixtures, even when they were heated up to l,000 F.(aluminum chloride sublimes at 361 F.). It was further noted that nohydrogen chloride was evolved during the reaction of the sodium form ofthe zeolite with the aluminum chloride. Portions of these products werewashed with water or dilute ammonium hydroxide and then dried andrecalcined at 800 F.

X-ray diffraction patterns showed little loss of structure for samplestreated at l,000 F. with, 0.l7 grams of aluminum chloride per gram offaujasite. Although the 8.7, and 7.5 A lines were weaker, the 5.7 and4.8A lines were stronger. It was further observed that the largerspacings tend to be restored when water is restored to the zeolite bywashing. The 0.17 g. of aluminum chloride per gram of faujasite is aboutthe amount required for the chlorine to be equivalent to the sodiumcontent of the faujasite. When larger amounts of aluminum chloride,e.g., 0.39 and 0.76 grams per gram of faujasite, were used, theintensities of the faujasite diffraction lines were decreasedconsiderably. The results of the X-ray examination of treated anduntreated sodium faujasite are summarized in Table 1 below.

TABLE I Portions of the above aluminum chloride treated products werewashed either by stirring them into water or into dilute ammoniumhydroxide solution and then washing on a filter, drying and calcining at800 F. The dilute ammonium hydroxide gave a rapid neutralization of thehydrochloric acid formed by the reaction of the metal chlorides withwater and reduced its harmful effect on the zeolite. The ammonia washedsamples were observed to result in better faujasite structures than theanhydrous aluminum chloride treated products unwashed. This effect wasshown to be greatest for those zeolites which were treated with largeamounts of aidminum chloride. The ammonium hydroxide washed productsalso had lower sodium contents. This furnishes a new procedure forreplacing the alkali metal in the zeolite and can be used to incorporatemetals which cannot be put into the zeolite by base exchange.

The treat with 0.76 g. of aluminum chloride resulted, after ammoniumhydroxide washing, in a product which gave a weaker faujasite patternthan base exchanged ammonium faujasite. This could indicate that thelevel of treatment was on the severe side. This material still retaineda fairly high surface area of 55 6 square meters/gram.

groups on the faujasite. The X-ray diffraction patterns of the anhydrousunwashed aluminum chloride treated sample showed some loss of structure.However, the ammonium hydroxide washed samples showed good faujasitestructures indicating little loss from the treatment. The resultingaluminum chloride treated hydrogen faujasites would have higher TABLE 11[Na faujasite treated with A1013, vapor and then washed] Grams AlCl alg.NaY 0.19 0. a9 0. 76

Calen. Washing NH4Y H2O NH4OH NH40I-I H1O None X-ray difir. linesIntensities of difir. lines 1 14.3 70 74 76 76 16 8 l 8. 7 54 50 39 2619 l 7. 5 29 39 31 21 11 l 5. 7 76 78 75 45 11 18 l 4.8 60 58 46 9 1 4.472 59 58 31 10 11 NaY Percent Na 10.0 2.5 a. 1 2. 64 1.7 Percent CL 0.65 1. 2 0.96 Percent Al 15.4 19.6 15.7 Surface area, M lg 840 690 666239 I Angstroms EXAMPLE 2 acidity than the calcined ammonium faujasitestarting materiutilizing 0.25 g. of ZrCl per gram of faujasite. Thechloride was stoichiometrically equivalent to the sodium in thefaujasite. A portion of the zirconium chloride treated sieve was thenwashed with dilute ammonium hydroxide solution as above. The X-raydiffraction data on samples of unwashed and washed zirconium chloridetreated faujasite were obtained. It was observed that treating sodiumfaujasite with zirconium chloride caused a large decrease in theintensity of the 7.5 to 14.3 A spacings, but a smaller decrease in the4.4 to 5.7 A spacings. Some decrease in these spacings would be expectedin all cases due to the dilution of the faujasite by the metal chlorideand possibly due also to the relatively greater X-ray adsorption bychlorine and zirconium atoms. The results of the X-ray diffraction testare summarized in Table III.

TABLE ll] Treatment of Na Faujasite X-ray diffr. Lines with ZrCl"Unwashed NH OH Washed 8.7 8 24 7.5 18 2| 5.7 57 59 4.8 30 3| 4.4 43 47:4 Cl l.3 S Area. 60

m.*lg. s50

' l6 hours treat at 700 F. of0.25 g. ZrCL/g. faujasite with occasionalmixing EXAMPLE 3 al. Thiswould indicate a higher level of catalyticactivity for acid catalyzed reactions. The results of the abovepreparation are summarized in the following Table IV.

TABLE IV Treatment of Calcined Ammonium Faujasite with AICI, at

0.19 g. AlCl lg. HY

Calcined AlCl, 'Washing N H,Y Treated Calcined NH Y Diffr. (800 F.) NoneNH,OH

Lines Intensity of X-ray Dit'fr. Lines EXAMPLE 4 This exampledemonstrates the treatment of a hydrogen form faujasite with zirconiumchloride utilizing the procedure of Example 1. As in Example 3 thehydrogen faujasite was prepared by calcining an ammonium exchangedfaujasite at 800 F. As in the previous example, it was observed thathydrogen chloride was evolved when the hydrogen faujasite treated withzirconium chloride was heated.

The zirconium chloride treated hydrogen faujasite was divided into twoportions, one of which was washed with water and the other with diluteammonium hydroxide solution. The water washed zirconium chloride sampleshowed some loss of structure. However, the ammonium hydroxide washedsample showed good faujasite structure which indicated little loss forthe treatment. The washed zirconium chloride treated products containedsurface areas of 634 and695 mF/g. and contained 0.97 and 0.75 percentchlorine, respectively. These samples further were observed to have verylow sodium-contents. The foregoing clearly indicates the utility ofthese zirconium chloride treated hydrogen faujasite samples as catalystsin acid catalyzed reactions. The results 'of the examination ofzirconium chloride treated hydrogen faujasite are summarized in Table V.

Treatment of Calcined Ammonium faujasite With ZrCl at 0.25 g. ZrClJg. HYCalcined Diffr. NI'LY ZrCl, Treated Calcined NI'LY Lines (800 F.) H,OWashed NH4OH Washed I43 A 70 72 72 4.4 72 27 52 71 Na 2.5 0.45 1.38 1 Cl0.97 0.75 SA mflg 840 634 695 For NaY calcined at 1000 F.

EXAMPLE 5 This example demonstrates the effect of a calcination stepsubsequent to the volatile metal halide treatment of the sodium form offaujasite.

A sodium form of faujasite was mixed with aluminum chloride so as togive a ratio of 0.17 g./g. of sodium faujasite. The mixture was thencalcined at 1,000 F. for a period of 3 hours. The calcined faujasite wasthen washed with water. This product was compared with samples of sodiumfaujasite which were treated at room temperature with solutions ofammonium chloride or dilute hydrochloric acid which contained the sameamount of chloride. The products were then washed.

It was observed that calcination with aluminum chloride appeared to makethe chlorine more difficult to remove by water washing, but littleeffect on the degree of removal of sodium was observed. The aluminumchloride sodium faujasite which had been calcined was observed to have ahigher residual chlorine content after washing than any of the othersamples tested. Washing with ammonium chloride was not observed to be aseffective in removing sodium as was the calcination with aluminumchloride and washing procedure. Dilute hydrochloric acid was aneffective reagent for the removal of sodium. However, the use of thisreagent caused a greater loss of faujasite structure than was observedfor the aluminum chloride treat followed by calcination and ammoniumhydroxide washing. The results of the foregoing experiments aresummarized below in Table VI.

TABLE VI- [Sodium removal from faujasite calcined at 1,000 F.]

Reagent 0.19 g. AlClalg. N a faujasite NHiCl H01 Calcln. None 1,000 F.None None None Washing H H20 NHtOH H20 H20 Percent Na 2. 83 3. 11 4. 024. 31 2. 84 Percent 01 0.15 0. 65 0. 13 0.05 0. 10

X-ray difir. lines Cl equivalent to Na. in fauiasite. After addinghalogencontair in g reagent. 7 V

EXAMPLE 6 inspection of the ferric chloride treated sodium faujasite isgiven below in Table VI].

TABLE V]! Treatment of Na Faujasile with FeCl, at 0.25 g. FeClJg.

Na Faujasite This example demonstrates the treatment of a hydrogenfaujasite with a titanium halide. The hydrogen faujasite was prepared bycalcining ammonium faujasite at 800 F. The halide form of titanium wastitanium trichloride. The amount of titanium chloride was 0.22 g. oftitanium chloride per gram of hydrogen faujasite (about one Cl peroriginal Na in the faujasite). The resulting titanium chloride treatedhydrogen faujasite was calcined at 600 F. to produce a catalyticallyactive form of this material. An active polymerization catalyst can bemade by treating this product with a metal alkyl or hydride, i.e., AIRAlHg, etc. Such treatments may also be used on zeolites which have beenreacted with VCl FeCl CrCl NiCl etc.

EXAMPLE 8 This example demonstrates the preparation of a silicon halidetreated hydrogen faujasite. The hydrogen faujasite was prepared in thesame manner as that indicated for Example 7.

The halogen form of silicon utilized in this example was silicontetrachloride. A total of 0.26 g. of silicon tetrachloride per gram ofhydrogen Y was vaporized in a stream of nitrogen and passed into thepreviously calcined zeolite at 400 F. over a period of 1.5 hours. Asample of this silicon tetrachloride treated hydrogen faujasite had achlorine content of 8.8 percent on analysis. A sample of the product waswashed with dilute ammonium hydroxide to yield a superior adsorbent orcatalytic material.

What is claimed is:

l. A method for treating crystalline aluminosilicate zeolites whilesubstantially maintaining their crystallinity which method comprisesreacting a crystalline aluminosilicate zeolite having exchangeablecations consisting essentially of cations selected from the groupconsisting of alkali metals and alkaline earth metals with a volatilehalide compound of an element less positive than the alkalis andalkaline earths whereby said halide compound is introduced into saidzeolite under anhydrous conditions.

2. The method of claim 1 wherein said volatile halide is selected fromthe group of metal halides consisting of the halides of aluminum,zirconium, titanium, tin, molybdenum, tungsten, chromium, vanadium,antimony, bismuth, iron, platinum group metals and the rare earths.

3. The method of claim 1 wherein said halides are selected from thegroup of nonmetal halides consisting of the halides of arsenic, silicon,boron and phosphorus.

4. The method of claim 1 wherein the halide treated crystallinealuminosilicate zeolite is calcined at elevated temperatures.

8. The method of claim 2 wherein the said volatile halide comprisesaluminum chloride.

9. The method of claim 2 wherein said volatile halide compriseszirconium chloride.

10. The method of claim 2 wherein said volatile halide comprises ferricchloride.

1 l. The method of claim 2 wherein said volatile halide comprisesplatinum chloride.

12. The method of claim 2 wherein said volatile halide comprisespalladium chloride.

13. The method of claim 2 wherein said volatile halide comprisestitanium chloride.

14. The method of claim 3 wherein, said volatile halide comprisessilicon tetrachloride.

15. The method of claim 1 wherein said volatile halide is reacted withsaid crystalline aluminosilicate zeolite at a temperature in the rangefrom about 400 to 1,200 F.

16. The method of claim 1 wherein said crystalline aluminosilicatezeolite is dried prior to said reaction with the volatile halide.

17. An improved crystalline aluminosilicate zeolite composition preparedby the method of claim 1.

18. A composition of matter comprising a crystalline aluminosilicatezeolite, said composition being prepared by reacting a crystallinealuminosilicate zeolite having exchangeable cations consistingessentially of cations selected from the group consisting of alkalimetal and alkaline earth metal cations with aluminum chloride vapors inan amount sufficient to yield a ratio of 0.5 to 1.5 equivalents ofaluminum chloride per equivalent of cation in said zeolite, whilemaintaining the crystallinity of said zeolite.

19. The composition of claim 18 wherein said aluminum chloride treatedcrystalline aluminosilicate zeolite is calcined and then washed toremove soluble halides.

20. The composition of claim 18 wherein said crystalline aluminosilicatecontains a metal hydrogenation component prior to being contacted withaluminum chloride vapors.

21. The composition of claim 20 wherein said metal hydrogenationcomponent comprises a platinum group metal.

22. In a method for treating crystalline aluminosilicate zeolites whilemaintaining their crystallinity by reacting a crystallinealuminosilicate zeolite having exchangeable cations consistingessentially of cations selected from the group consisting of alkalimetals and alkaline earth metals, with a volatile halide compound of anelement less positive than the alkali metals and alkaline earth metalswhereby said halide compound is introduced into said zeolite underanhydrous conditions, the improvement comprising subsequently washingthe said volatile halide treated zeolite to remove soluble halides.

23. A composition of matter comprising a crystalline aluminosilicatezeolite, said composition being prepared by reacting a crystallinealuminosilicate zeolite having exchangeable cations consistingessentially of cations selected from the group consisting of alkalimetal and alkaline earth metal cations with aluminum chloride vapors inan amount sufficient to yield a ratio of 0.5 to 1.5 equivalents ofaluminum chloride per equivalent of cation in said zeolite, whilemaintaining the crystallinity of said zeolite, and calcining and washingsaid aluminum chloride treated crystalline aluminosilicate zeolite toremove soluble halides.

24. The method of claim 22 wherein said washing comprises the use ofdilute ammonium hydroxide solution.

2. The method of claim 1 wherein said volatile halide is selected fromthe group of metal halides consisting of the halides of aluminum,zirconium, titanium, tin, molybdenum, tungsten, chromium, vanadium,antimony, bismuth, iron, platinum group metals and the rare earths. 3.The method of claim 1 wherein said halides are selected from the groupof nonmetal halides consisting of the halides of arsenic, silicon, boronand phosphorus.
 4. The method of claim 1 wherein the halide treatedcrystalline aluminosilicate zeolite is calcined at elevatedtemperatures.
 5. The method of claim 1 wherein the volatile halidecontains 0.1 to 3.0 atoms of halogen per atom of exchangeable cation inthe zeolite.
 6. The method of claim 1 wherein said volatile halidetreated zeolite is subsequently washed to remove soluble halides.
 7. Themethod of claim 6 wherein said washing comprises the use of diluteammonium hydroxide solution.
 8. The method of claim 2 wherein the saidvolatile halide comprises aluminum chloride.
 9. The method of claim 2wherein said volatile halide comprises zirconium chloride.
 10. Themethod of claim 2 wherein said volatile halide comprises ferricchloride.
 11. The method of claim 2 wherein said volatile halidecomprises platinum chloride.
 12. The method of claim 2 wherein saidvolatile halide comprises palladium chloride.
 13. The method of claim 2wherein said volatile halide comprises titanium chloride.
 14. The methodof claim 3 wherein said volatile halide comprises silicon tetrachloride.15. The method of claim 1 wherein said volatile halide is reacted withsaid crystalline aluminosilicate zeolite at a temperature in the rangefrom about 400* to 1,200* F.
 16. The method of claim 1 wherein saidcrystalline aluminosilicate zeolite is dried prior to said reaction withthe volatile halide.
 17. An improved crystalline aluminosilicate zeolitecomposition prepared by the method of claim
 1. 18. A composition ofmatter comprising a crystalline aluminosilicate zeolite, saidcomposition being prepared by reacting a crystalline aluminosilicatezeolite having exchangeable cations consisting essentially of cationsselected from the group consisting of alkali metal and alkaline earthmetal cations with aluminum chloride vapors in an amount sufficient toyield a ratio of 0.5 to 1.5 equivalents of aluminum chloride perequivalent of cation in said zeolite, while maintaining thecrystallinity of said zeolite.
 19. The composition of claim 18 whereinsaid aluminum chloride treated crystalline aluminosilicate zeolite iscalcined and then washed to remove soluble halides.
 20. The compositionof claim 18 wherein said crystalline aluminosilicate contains a metAlhydrogenation component prior to being contacted with aluminum chloridevapors.
 21. The composition of claim 20 wherein said metal hydrogenationcomponent comprises a platinum group metal.
 22. In a method for treatingcrystalline aluminosilicate zeolites while maintaining theircrystallinity by reacting a crystalline aluminosilicate zeolite havingexchangeable cations consisting essentially of cations selected from thegroup consisting of alkali metals and alkaline earth metals, with avolatile halide compound of an element less positive than the alkalimetals and alkaline earth metals whereby said halide compound isintroduced into said zeolite under anhydrous conditions, the improvementcomprising subsequently washing the said volatile halide treated zeoliteto remove soluble halides.
 23. A composition of matter comprising acrystalline aluminosilicate zeolite, said composition being prepared byreacting a crystalline aluminosilicate zeolite having exchangeablecations consisting essentially of cations selected from the groupconsisting of alkali metal and alkaline earth metal cations withaluminum chloride vapors in an amount sufficient to yield a ratio of 0.5to 1.5 equivalents of aluminum chloride per equivalent of cation in saidzeolite, while maintaining the crystallinity of said zeolite, andcalcining and washing said aluminum chloride treated crystallinealuminosilicate zeolite to remove soluble halides.
 24. The method ofclaim 22 wherein said washing comprises the use of dilute ammoniumhydroxide solution.